Fading Images on Thermal Paper
User Experience Network™ [Health Devices Oct 1990;19(10):374-5]
We have received several reports of fading images on thermal paper used
with the thermal printers in electronic sphygmomanometers and ECG monitors. Although the
initial images were good, they faded after a few months in storage. Because patient
records are usually kept for years, loss of diagnostic traces can create medical and legal
Basic thermal paper, a layered composite of base paper, thermal coating,
and protective coating, is produced by several manufacturers and is subsequently
reprocessed by many different suppliers for use in various recording devices. Reprocessing
includes adding artwork, cutting and trimming, rolling or folding, perforating, or
otherwise reworking the basic paper. Although most paper manufacturers rigorously test
their thermal papers and expect them to preserve an image for at least five years, poor
reprocessing techniques can alter the paper's characteristics, thereby reducing its image
Images are produced when a small area of the paper is heated, creating a
chemical reaction that causes a color change in the paper's thermal coating. The
performance characteristics (e.g., image quality, effect on thermal printer, image life)
of paper from different manufacturers or from different lots can vary because of the
variety and combination of binders, dye precursors, color formers, artwork inks, paper
fillers, and protective coatings. The specific materials used to make thermal papers are
Other factors that affect the paper's image life include environmental
effects and the paper's sensitivity to temperature, humidity, and light. Also, the organic
chemicals used in the coatings react to a number of solvents and plastics found in
hospitals. Some manufacturers and suppliers provide warnings about these hazards, common
to all thermal papers; however, these warnings are not always obvious or well known to
users or to personnel in the medical records department.
The recording device or printer manufacturer, or a reliable after-market
supplier, typically matches thermal papers and devices or printers to achieve the best
image quality and produce the least effect on the printer. Using untested paper with an
unmatched thermal printer can cause poor image quality and damage the printer.
- For the best image quality and thermal printer
life, choose a paper specifically recommended by the recording device
manufacturer for use in the printer. Most device manufacturers can recommend
several brands of thermal paper that work well with the printers in their
equipment. Another safe choice is to purchase paper offered by after-market
suppliers who will warrant the paper and printer against damage from the use
of their product.
- Photocopy any especially critical printed thermal
paper records that must be kept for longer than six months. Plain bond
photocopies last far longer than thermal paper. Keep the original record and
the photocopy; these can be compared to gauge image life and to assess any
alterations, other than fading, that may have occurred to the original
- Keep thermal paper away from organic liquids and
vapors (e.g., alcohol, solvents, plasticizers, petroleum products) that
cause the image to fade or the thermal coating to discolor. Careless
cleaning of thermal printers, storing thermal paper with carbon or
carbonless paper, contacting thermal paper with adhesive tape or prep pads,
or storing different grades of thermal paper together are a few practices
that can cause organic materials to damage thermal paper and images.
- Store unused thermal paper in its original
container in cool, dry, dark places to preserve its chemical and physical
characteristics. Excessive heat, moisture, or light can alter the quality of
the thermal paper. Normal office conditions (72° F, 45% RH) are best.
- To preserve the image, store printed thermal paper
in manila folders or envelopes away from plastic folders, binders, or boxes.
Also protect printed paper from excessive heat, humidity, and light.
- For further information, contact your printer manufacturer or paper
supplier. If you have difficulty obtaining information, try to contact one
of the larger thermal paper manufacturers.
ECG Monitors [12-599]
Paper, Recording [15-639]
Paper, Recording, ECG [16-754]
Sphygmomanometers, Electronic [16-157]
Cause of Device-Related Incident
Device factors: Design/labeling error; Failure of accessory
External factor: Environmental
Mechanism of Injury or Death